From the shooting of sperm darts to post-coital cannibalism, there is not much that surprises researchers into the weird ways of animal sex.

And it’s all good! But here’s something new:

[O]n Wednesday, biologists said they have witnessed a behaviour so weird that it warrants scientific mention: a creature which procreates by jabbing a needle-like “penis” into its own head.

Glory to the intelligent designer! Want more information? Sure you do. Here it is:

The bizarre beast is a microscopic, water-dwelling flatworm dubbed Macrostomum hystrix, a team reported in the journal Proceedings of the Royal Society B. And they theorised it may have evolved the unconventional method of self-impregnation in order to procreate “under conditions of low mate availability.”

M. hystrix is a transparent worm about one millimetre (0.04 of an inch) long — a hermaphrodite with both male and female reproductive organs. Normally, they exchange sperm with others of their kind using a needle-like protrusion called a “stylet”, which pierces the partner’s outer body membrane in a method known to scientists as “traumatic wounding”.

A “stylet” — we like that! Here’s more:

But when sex partners are scarce, it seems, these worms can turn their stylets, located in the tail section, on themselves.

We don’t see anything wrong with that. One more excerpt:

The findings indicated that when deprived of a mate, M. hystrix self-injects sperm “including or even exclusively into their own head region,” said the team. The sperm migrates from there to the site of fertilisation in the centre of the tiny body.